docs: def to_pygsp(self, **kwargs):
          """Convert to a PyGSP graph
  
          For use only when the user means to create the graph using
          the flag `use_pygsp=True`, and doesn't wish to recompute the kernel.
          Creates a graphtools.graphs.TraditionalGraph with a precomputed
          affinity matrix which also inherits from pygsp.graphs.Graph.
  
          Parameters
          ----------
          kwargs
              keyword arguments for graphtools.Graph
  
          Returns
          -------
          G : graphtools.base.PyGSPGraph, graphtools.graphs.TraditionalGraph
          """
          from . import api
          if 'precomputed' in kwargs:
              if kwargs['precomputed'] != 'affinity':
                  warnings.warn(
                      "Cannot build PyGSPGraph with precomputed={}. "
                      "Using 'affinity' instead.".format(kwargs['precomputed']),
                      UserWarning)
              del kwargs['precomputed']
          if 'use_pygsp' in kwargs:
              if kwargs['use_pygsp'] is not True:
                  warnings.warn(
                      "Cannot build PyGSPGraph with use_pygsp={}. "
                      "Use True instead.".format(kwargs['use_pygsp']),
                      UserWarning)
              del kwargs['use_pygsp']
          return api.Graph(self.K,
                           precomputed="affinity", use_pygsp=True,
                           **kwargs)